Solid state relay comes on with +5v, but doesnt turn off?

[Nick]

I have an omron solid state relay for 120vac, I'm testing with DC LEDs to see if it works. It does turn on, but will not turn off unless I pull the power.

Nick

[newguy]

A SSR is usually constructed out of a triac or something like that. A triac will start to conduct when current is fed into the trigger, and won't stop until the *controlled* (switched) voltage falls to zero.

What you're seeing is normal. Try it with a light bulb - you'll see that it turns off when the mains ac voltage falls to zero (after removal of the trigger).

[John Morley]

Nick,

A quick google search indicates that there are "AC output", "DC Output" and "Universal (AC/DC) Output" solid state relays. Yours seems to be the AC only variety. Some SSR's apparently require the zero-crossing of the AC signal to switch properly.
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John Morley

[Nick]

Thanks for the info!

Nick